Contact arrangement for control relay



Dec. 11, 195% R. A. PELZ ET AL 2,773,948

CONTACT ARRANGEMENT FOR CONTROL RELAY Filed July 29, 1953 5 Sheets-Sheet1 Fig.1.

\ WETNESSES: INVENTORS 5.4 I Robert A. Pelz Wj 0nd Delberi' Ellis.

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ATTORNEY 1%., 1956 R. A. PELZ ET AL 29773994?) CONTACT ARRANGEMENT FORCONTROL RELAY Filed July 29, 1953 3 Sheets-Sheet 2 Fig.6

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ATTORNEY 3 Sheets-Sheet 3 Filed July 29, 1953 lNJENTORS s 4 mm M DIE Awm m D f Ow W ATTORNEY United States Patent CONTACT ARRANGEMENT FORCONTROL RELAY Robert A. Pelz and Delbert Ellis, Beaver, Pa., assignorsto Westinghouse Electric Corporation, East Pittsburgh, Pa., acorporation of Pennsylvania Application July 29, 1953, Serial No.378,994

11 Claims. (Cl. 200-16) This invention relates to a contact assembly forcontactors and more particularly, this invention relates to a contactassembly which is reversible as a unit from make to break or break tomake.

In the past, contactors of the type illustrated herein have not hadcontacts that were interchangeable from make to break and break to makewith the same parts. Other contactors have been provided with contactswhich are reversible from make to break or break to make, but thesecontact assemblies have been somewhat complex, have had several partswhich require adjustment to reverse, and have parts for the make tobreak position which are unused for the break to make position or viceversa. It is a distinct disadvantage if a number of loose parts whichmay be lost while handling, or if a number of extra parts which must bestored, must be used to change contacts from normally open to normallyclosed or from normally closed to normally open.

it is an object of this invention to provide a contact assembly which isreversible as a unit from make to break or break to make with the sameparts.

Another object of this invention is to provide a contact assemblystructure which is of a simple and economic construction and which hasparts that are so disposed as to be of relatively simple and quickassembly and dis assembly.

Yet another object of this invention is to provide a reversible contactassembly structure for a contactor which is of a simple and economicconstruction which has parts that are so disposed as to be of relativelysimple and quick assembly and disassembly.

The objects recited are merely illustrative. Other objects andadvantages will become more apparent from a study of the followingspecification and the accompanying drawings in which:

Figure 1 shows a front view of an assembled electromagnetic contactorcontaining the contact assembly;

Fig. 2 shows a sectional side View of an assembled electromagneticcontactor containing one embodiment of the contact assembly in anormally closed position;

Fig. 3 shows a detailed view of one embodiment of a contact assembly ina normally open position, and contact assembly mounting means;

Figs. 4 and 5 show another embodiment of the con tact assembly means inthe normally closed and the normally open positions respectively; and

Fig. 6 shows a top view of the movable contact member used in thecontact assemblies.

For the purpose of illustrating the utility of embodiments of thereversible contact assembly, it is shown and described as being used inthe relay or contactor for which it was originally designed. The detailsof the relay are shown and described in more detail in a copendingapplication of Vincent G. Krenke and Delbert Ellis filed March 6, 1953,entitled Electromagnetic Contactor and given Serial No. 340,862 whichshows an improvement of the contactor shown and described in the twocopending applications of Owen L. Taylor filed March 6, 1953, entitledElectromagnetic Contactor and given Serial Numbers 340,859 and 340,860.

By referring to the drawings, it will be noted that base plate 2 isprovided with displaced portions 3, 4 and 4. The displaced portions 3and 4 have holes therein for receiving bolts to fix the base plate ofthe relay to a panel board. A resilient flat spring member 5 is providedon the back of the base plate so that the displaced portions 3, 4 and 4and the resilient spring member 5 will give a snug fit with a panelboard when the contactor is fixed thereto. This means of mountingpermits positive mounting with only two mounting screws or bolts onsurfaces which may not be perfectly fiat. The resilient spring member 5also absorbs the shock from the closing action of the contactor whichdecreases the armature and magnet face wear and increases the operatinglife of the contactor.

A bearing bracket 7 and'electromagnet brackets 8 are also fixed to thebase member 2. The electromagnet brackets 8 fit on each side of theelectromagnet core 1 to hold the laminations together. A portion of eachelectromagnet bracket 8 extends perpendicular to the plane of thelaminations and away from the core 1 so that the brackets may be fixedto the base member 2 and thus hold the core 1 in position. A coil 9 isprovided on the center leg of the E-shaped electromagnet.

The bearing bracket 7 is one of four plates which form a parallelogramarrangement. The bearing bracket 7 has bearing surfaces at each endwhich are engaged by bearing edges of an upper rocker arm 19 and a lowerrocker arm 11, respectively. The opposite bearing edge of the upperrocker arm 10 engages a bearing surface of the armature bracket 12 andthe bearing edge of the opposite end of the lower rocker arm 11 engagesthe lower bearing surface of the armature bracket 12. The armaturebracket 12 has a mounting bolt 13 projecting through two extensions onthe armature bracket to secure the armature 14 of the contactor betweenthe extensions. Extensions at the upper end of the armature bracket 12are fixed to a contact actuating arm or support 15 by means of screws16. The contact actuating arm has wall portions 15 which mate with wallportions 17 of the contact support means 6. The mating wall portions 15'and 17 increase the arc path between the contacts.

When the coil 9 is energized it causes the armature 1G to pick up andthus transmit motion through the parallelogram arrangement to theactuating arm 15. The contact assemblies 18 are actuated by the contactactuating arm 15 and thus the movable contacts of the contact assemblies18 either bridge the fixed contacts 25 supported by the contact supportmeans 6 or open the circuit between the fixed contacts. The coil 9 isheld in position on the center leg of E-shaped electromagnet by means ofspring members 19 fixed to the electromagnet bracket 8 on the sides ofthe electromagnet. The spring members 19 are fixed in such a manner thatthey may be rotated out of contact with the coil 9 to allow easy removalof the coil.

Figs. 2 and 3 show views of sections through the recesses in the contactsupport means 6. The contact assembly 18 is shown in its normally closedposition in Fig. 2 and in its normally open position in Fig. 3. The

stationary contact members 25 are held in position by the screws 26. Theterminals 27 are brought out above contact support means 6 so that theyare readily accessible. The movable contact members 28 have fourrecesses along the sides which mate with the guide links 34) on thesaddles 29.

In the normally open contact position shown in Fig. 3, the threaded endof the screw 31 enters a tapped saddle guide 32 and fastens the movingcontact assembly 18 to the contact actuating arm 15.

greases The saddle 29 is formed at both ends. The bend at one endcontains a clearance hole for mounting in the normally open position.The bend at the other end forms a large area which, when in contact withthe actuating arm 15 during its travel assures little wear of theactuating arm surface and thus assures a long reliable life. A biasingspring 33 is provided between the bridging movable contact members 25and the saddle guide 32, in order to hold the movable contacts 28 inposition and assure good contact. The contacts spring pressure may bevaried to produce a loading more in line with the particular magnetdesign. If the movable contact assembly 18 is normally open as is shownin Fig. 3, when the armature 14 is picked up, the movable contacts 23are forced to bridge the stationary contacts 25. The normally closedcontact assembly, as shown in Fig. 2, is such that movement of thecontact actuating arm 15 will move the saddle member 29 upward and thuscause the movable contacts 28 to be lifted from the stationary contactmembers 25. The configuration of the contact actuating arm 15, thesaddle guide member 32, the sad dle 29 and the contact support means 6is such and the interrelationship of these parts is such that the saddlemember 29 can be clamped only in the one position giving the rightcontact gap, alignment, and travel for the contacts in either thenormally open or the normally closed arrangement.

To change from a normally open to a normally closed contact assembly itis merely necessary to remove the two mounting screws 16 for the contactactuating arm 15, remove the mounting screw 31 for the saddle guidemember 32, invert the entire movable contact assembly 18 and place inthe position shown in Fig. 2. The mounting screw 31 for the saddle guidemember 32 loses its mounting function for the normally closed positionof the contact assembly 18, since the contact biasing spring 33 willhold the assembly in position when the contacts are either closed oractuated by the contact actuating arm 15. The mounting screw 31 extendsthrough a clearance hole in the fixed contact support means 6 and into atapped hole provided in the saddle guide member or retainer 32 so thatthe contacts will be closed. The design is such that it is possible toassemble only in the correct position and with the minimum of wastedmotion.

Figs. 4 and show another embodiment of the movable contact assemblywhich may be used. The components are the same as those shown for thepreviously described embodiments except that a special screw 40 is usedinstead of the screw 31.

For a normally open contact, the contact assembly 18 is positioned inthe same manner as previously described and the screw 40 holds thecontact assembly 18 to the contact actuating arm 15 in the same manneras did the screw 31 in the previous embodiment.

In the normally closed contact position, Fig. 5, the screw 40 also losesits mounting function, but in the embodiment shown, the screw 40 isthreaded into the saddle guide 32 until the shoulder is tight againstthe saddle guide 32. The screw 40 is of a special construction which hasa head that will be in clearance with the clearance hole in the saddle29. Thus, the screw is retained for future use in the movable contactassembly 18 making it unnecessary to provide a threaded insert in thebase or other special retaining means. It may, howeevr, be necessary tomake the clearance hole in the saddle 29 larger for the embodiment ofFigs. 4 and 5 than for the embodiment previously described.

It will be appreciated that the embodiment of Figs. 4 and 5 have all ofthe advantages described for the embodiment of Figs. 2 and 3.

It will be recognized that the objects of the invention have beenachieved by providing a contact assembly which'is simple, has a minimumnumber of parts and which is easily reversed in a contactor as a unitfrom normally open to normally closed and vice versa. The

42 contact assembly has no loose parts to be lost while handling anddoes not require extra parts for either position which must be stored.

While in accordance with the patent statutes, one best known embodimentof the invention has been illustrated and described in detail, it is tobe understood that the invention is not limited thereto or thereby, butthat the inventive scope clearly includes equivalents.

We claim as our invention:

1. In an electric circuit controlling device, a contact supportingmeans, stationary contact members fixed to said contact supportingmeans, movable contact means for bridging said stationary contactmembers, a contact actuating arm, a saddle member formed to be U-shapedat both ends and having openings in both sides, a saddle guide adaptedto slidably cradle in one U-shaped end of said saddle member, saidmovable contact means having portions adapted to extend into theopenings in the sides of said saddle member to guide the motion of themovable contact means relative to the saddle member, a resilient biasingmeans, said resilient biasing means being positioned between the movablecontact means and the saddle guide to bias said movable contact meansand said saddle guide into position and make a unitary structure withsaid saddle member, said saddle guide being connected to the contactsupporting means for normally closed contact operation and the end ofsaid saddle member adjacent said saddle guide being connected to saidcontact actuating arm for normally open contact operation.

2. In an electric circuit controlling device, a Contact supportingmeans, stationary contact members fixed to said contact supportingmeans, movable contact means for bridging said stationary contactmembers, a contact actuating arm having a hole therein, a saddle memberformed to be U-shaped at both ends and having openings in both sides,said saddle member also having a hole in one U-shaped end, a saddleguide adapted to slidably cradle in said one U-shaped end of said saddlemember, said saddle guide having a tapped hole in alignment with saidhole in the saddle member, said movable contact means having portionsadapted to extend into the openings in i the sides of said saddle memberto guide the motion of the movable contact means relative to the saddlemember, a resilient biasing means, said resilient biasing means beingpositioned between the movabie contact means and the saddle guide tobias said movable contact means a "1 said saddle guide into position andmake a unitary structure with said saddle member, a screw adapted topass through said hole in said contact actuating arm, through theclearance hole in the saddle member and threaded into the tapped hole inthe saddle guide member to connect the contact assembly to the contactactuating arm with said movable contact means spaced from saidstationary contact members, normally closed contact operation beingobtained by inverting said saddle member and mounting said saddle guideon said contact supporting means with said movable contact meansbridging said stationary contact members, the remaining end of saidsadthe member being disposed adjacent said contact actuating arm forengagement and operation thereby.

3. In an electric circuit controlling device, a contact supporting meanshaving a hole therein, stationary contact members fixed to said contactsupporting means, movable contact mcans for bridging said stationarycontact members, a contact actuating arm, a saddle member formed to beU-shaped at both ends and having openings in both sides, a saddle guideadapted to slidably cradle in one U-shapcd end of said saddle member,said saddle guide having a tapped hole adjacent one end thereof, saidmovable contact means having portions adapted to extend into theopenings in the sides of said saddle member to guide the motion of themovable contact means relative to the saddle member, a resilient biasingmeans, said resilient biasing means being positioned between the movablecontact means and the saddle guide to bias said movable contact meansand said saddle guide into position and make a unitary structure withsaid saddle member, a screw adapted to pass through said hole in saidcontact support means and said tapped hole in the saddle guide toconnect the contact assembly to the fixed contact support means withsaid movable contact means engaging said stationary contact members andwith the remaining end of said saddle member disposed adjacent saidcontact actuating arm for engagement and actuation thereby, normallyopen contact operation being obtained by inverting said saddle memberand securing said one end of said saddle member to said contactactuating arm with said movable contact means spaced from saidstationary contact members.

4. In an electric circuit controlling device, a contact supportingmeans, stationary contact members fixed to said contact supportingmeans, movable contact means for bridging said stationary contactmembers, a contact actuating arm, a saddle member formed to be U-shapedat both ends and having openings in both sides, a saddle guide adaptedto slidably cradle in one U-shaped end of said saddle member, saidmovable contact means having portions adapted to extend into theopenings in the sides of said saddle member to guide the motion of saidmovable contact means relative to the saddle member, a resilient biasingmeans, said resilient biasing means being positioned between the movablecontact means and the saddle guide to bias said movable contact meansand said saddle guide into position and make a unitary structure withsaid saddle member, said saddle guide being mounted on said contactsupporting means and positioning said saddle member so that the movablecontact means bridges said stationary contact members and said resilientbiasing means biases said saddle guide into engagement with saidstationary contact supporting means to hold the contact assembly inposition, the end of said saddle member opposite said one end thereofbeing disposed adjacent said contact actuating arm to be engaged andactuated thereby.

5. In an electric switch, a stationary support, a movable supportmovable along a path toward and away from said stationary support, apair of spaced stationary contcts insulatedly supported on saidstationary support, a movable contact bridge, a saddle member slidablymounting said movable contact bridge, means for limiting slidingmovement of said contact bridge toward one end of said saddle member, asaddle guide slidably engaging said saddle member, means for limitingsliding movement of said saddle guide toward the other end of saidsaddle member, resilient biasing means disposed between said movablecontact bridge and said saddle guide and bias ing said movable contactbridge and said saddle guide to their respective limits of movement onsaid saddle member, said movablecontact bridge being spaced from saidstationary contacts along the path of movement of said movable memberfor normally open contact operation in a first position of said saddlemember in which said other end of said saddle member is secured to saidmovable member, and being disposed for normally closed contact operationwith said movable contact bridge bridging said stationary contacts withsaid saddle member inverted from said first position and said saddleguide being supported on said stationary support, in said invertedposition of said saddle member said one end thereof being disposed inthe path of movement of said movable member to be engaged and actuatedthereby.

6. An electric switch having an invertible movable contact assemblyproviding selective normally open and normally closed contact operationcomprising, a stationary support, a movable support movable along a pathtoward and away from said stationary support, spaced stationary contactsinsulatedly mounted on said stationary support, a saddle member, acontact bridge slidably engaging said saddle member, a saddle guideslidably engaging said saddle member, spaced stop means on said saddlemember, resilient biasing means disposed between said contact bridge andsaid saddle guide and biasing said contact bridge and saddle guidetoward opposite ends of said saddle member against said respectivespaced stop means, means providing mounting of said saddle member in afirst position with the end of said saddle member adjacent said saddlebracket secured to said movable member and with said contact bridgespaced from said stationary contacts to provide normally open contactoperation, and means providing mountingof said saddle guide on saidstationary support with said saddle member inverted from said firstnamed position and said contact bridge engaging said stationarycontacts, the end of said saddle member opposite said saddle guide beingdisposed in the path of movement of said movable support for actuationthereby.

7. An electric switch having an invertible moving contact assemblyproviding selective normally open and normally closed contact operationcomprising, a stationary support, a movable support movable along a pathtoward and away from said stationary support, a stationary contactmounted on said stationary support, a movable contact mount, a movablecontact slidably mounted on said mount, a guide slidably engaging saidmount, resilient means disposed between said movable contact and saidguide and resiliently biasing said movable contact and guide to givenspaced positions on said mount, said mount providing normally opencontact operation in a first position with the end thereof adjacent saidguide secured to said movable support and providing normally closed contact operation in a position inverted with respect to said firstposition in which said guide is secured to said stationary support withsaid moving contact engaging said stationary contact and with the end ofsaid mount adjacent said moving contact confronting said movable supportto be actuated thereby.

8. An electric switch having an invertible movable contact assemblyproviding selective normally open and normally closed contact operationcomprising, an elongated movable contact mount, having axially spacedconfronting stops thereon, a movable contact slidably disposed on saidmount between said stops, a guide slidably disposed on said mountbetween said stops, resilient means compressed between said guide andsaid movable contact and biasing said guide and movable contact againstsaid respective stops, a stationary support having a guide seat thereon,a stationary contact mounted on said stationary support and spaced fromsaid guide seat, a movable support movable between inoperative andoperative positions along a path directed toward said stationarycontact, the distance between said movable support in said inoperativeposition and said stationary contact being greater than the distancebetween the end of said mount adjacent said guide and said movablecontact and the distance between said guide seat on said stationarysupport and said stationary contact being less than the distance betweensaid guide and said movable contact, said movable contact assemblyproviding normally open contact operation in a first position with theend of said mount adjacent said guide secured to said movable support,and providing normally closed contact operation in a position invertedwith respect to said first position in which said guide is secured insaid guide seat with said moving contact engaging said stationarycontact and with the remaining end of said mount confronting saidmovable support to be actuated thereby.

9. An electric switch having an invertible movable contact assemblyproviding selective normally open and normally closed contact operationcomprising, a movable contact assembly including an elongated movablecontact mount, a movable contact slidably mounted on said elongatedmount, a stop on said elongated mount, and a spring on said mount havingan end adjacent one end of said mount and the other end engaging saidmovable contact and spring loading said movable contact against saidstop; a stationary support, a movable support movable from a normalposition to an operated position along a path shrines toward saidstationary support, a stationary contact disposed between saidstationary support and said movable support and having opposite contactf-aces respectively confronting said movable support and said stationarysupport, means providing mounting said movable contact assembly in afirst position with said one end of said elongated mount secured .tosaid movable support and with said movable contact spaced from one faceof said stationary contact for normally open contact operation, andguide means secured to said stationary support and slidably mountingsaid one end of said elongated mount on said stationary support in aposition inverted with respect to said first position, said guide meansoperably engaging said spring to spring load said movable contactagainst the opposite face of said stationary contact, the other end ofsaid elongated mount being disposed adjacent to and in confrontingrelation with said movable support to be actuated thereby by movement ofsaid movable support from said normal position toward operated position.

10. An electric switch having an invertible movable contact assemblyproviding selective normally open and normally closed contact operationcomprising, a stationary support, a movable support having a surfaceconfronting said stationary support, means for moving said movablesupport from a normal position to an operated position along a pathtoward said stationary support, a stationary contact disposed betweensaid stationary and movable supports and being closer to said stationarysupport than said movable support when said movable sup port is in saidnormal position, a movable contact, an elongated mount slidably mountingsaid movable contact, a pair of axially spaced stops on said elongatedmount, a guide slidably engaging said elongated mount, a compressionspring disposed between said guide and said movable contact and springloading said guide and said movable contact against said respectivestops, means providing mounting of said elongated mount in a firstposition in which the end of said elongated mount adjacent said guide isdisposed on said surface of said movable support, said movable contactin said first position of said elongated mount being spaced from saidstationary contact and being engageable therewith by movement of saidmovable support from said normal position toward operated position, andmeans providing mounting of said guide on said stationary support withsaid elongated mount inverted with respect to, said first position andwith said movable contact engaging said stationary contact, in saidinverted position of said elongated mount the end thereof remote fromsaid guide being disposed in confronting relation with respect to saidsurface of said movable support for engagement by said surface uponmovement of said movable support from said normal position towardoperated position.

11. An electric switch having an invertible movable contact assemblyproviding selective normally open and normally closed contact operationcomprising, a stationary support, a movable support having a surfaceconfronting said stationary support, means for moving said movablesupport from a normal position to an operated position along a pathtoward said stationary support, a stationary contact disposed betweensaid stationary and movablesupports and being closer to said stationarysupport than said movable support when said movable support is in saidnormal position, the opposite faces of said stationary contactrespectively confronting said stationary support and said movablesupport, a movable contact assembly including an elongated movablecontact mount, a movable contact slidably mounted on said elongatedmount, a stop on said elongated mount, and a spring on said elongatedmount having one end adjacent one end of said elongated mount and theother end engaging said movable contact and spring loading said movablecontact against said stop; means providing mounting of said movablecontact assembly in a first position with said one end of said elongatedmount secured to said surface of said movable support and with saidmovable contact spaced from one face of said stationary contact fornormally open contact operation; and guide means slidably mounting saidone end of said elongated mount on said stationary support in a positioninverted with respect to said first position, said guide means operablyengaging said spring to spring load said movable contact against theopposite face of said stationary contact, the other end of saidelongated mount confronting said surface of said movable support to beactuated thereby by movement of said movable support from said normalposition toward operated position.

References Cited in the file of this patent UNITED STATES PATENTS2,208,387 Pierce July 16, 1940 2,276,698 Pierce Mar. 17, 1942 2,304,972Van Valkcnburg et al Dec. 15, 1942 2,310,056 Bendz Feb. 2, 19432,419,072 Hall Apr. 15, 1947 2,589,167 Van Valkenburg et al. Mar. 11,1952 FOREIGN PATENTS 470,532 Great Britain Aug. 17, 1937

